Can anybody tow/impound my car without my permission?

[Ginika]

Ok I have a very serious problem, on Saturday December 10 2011 i was going to work at the aurora mall and i was going to park my car. As I was going to park there was ice on the ground, so my car kind of slipped on my tires and scratched the back side of another car as I parked. I am an 18 year old kid and I've never been in this situation before so because I was running late for work I just left to go to work. (I know that was a wrong move) Ok then i got off work at 10 that night to go home and relax after a long day... to see that my car was not there.. I was pissed and angry so I called my dad and we went to the police station to file a stolen vehicle report, as we were filling the report the lady at the desk looked up the car.. then told us that it was towed on an alleged hit and run incident. We were like um ok so she gave us the number to the impound man, and the next day we called. My dad talked to him and told me that he said that it wasn't a big deal and that it wasn't a hit and run because my car was right next to the other one so he said that he gave the report to his boss and then that they would call and I would have to come in and write a statement and they would release the car....Ok
but see my problem and my question is how can they have the right to tow/impound my car that night without my permission? They didn't contact me or anybody so what if I wasn't able to get home that night? Because of me not having my car I have missed a couple days of school, can I report that? They don't have evidence that the scratch was mine as well? Can I sue, How should I handle this situation please and thank you?